Call me paranoid.
My gut instinct is to not touch anything resembling "fossil" or "ivory" with a ten-foot pole until this legal stuff clears up. Which may or may not happen.... if I were a gambling man, I'd bet on "not".
You may think I'm being overly-cautious... but some years ago one of the finest, oldest and largest manufacturers of high-end guitars in America (Gibson) found themselves in a HEAP of trouble over "provenance" of "exotic woods". "Proving" the paperwork is in order is not nearly as simple as it might seem. As I recall, they got most of their stock back eventually, but the interruption of business, legal costs, and so forth was
extremely costly and time-consuming. Gibson is a multi-million-dollar company with powerful resources, and they were seriously spooked... That's the kind of thing that could completely shut-down a smaller shop for good.
What's so great about ivory or dinosaur tusk, anyway? Is one knife job worth risking your freedom or a boatload of hassle and costs, on the off-chance that some over-zealous nitwit gets wind of you using "banned" material? Can you really
prove where it came from? Do you want to be a test-case or a notch in the belt of some goof trying to make a name for him/herself? (And believe you me, "pre-ban" definitely shows up on their radar... believe it or not, their are people with nothing better to do than internet-search these terms... and ShopTalk pops right up)
Meanwhile, I would advise visiting the resources provided by the
American Knife & Tool Institute and
KnifeRights to keep track of exactly what's legal, rather than rely on any hearsay. Even then, there's some grey area and to a certain extent, you're still on your own if someone comes after you.
I also very strongly recommend joining both those organizations. They're working hard to stick up for us, and clarify/strike down wacky laws.